en Copyright 2015 Java http://172.16.0.5:8080/history/linux-6.15/arch/csky/lib/error-inject.c#71e193d7 csky: Add support for function error injectionInspired by the commit 42d038c4fb00 ("arm64: Add support for functionerror injection"), this patch supports function error injection forcsky.This patch mainly support two functions: one is regs_set_return_value()which is used to overwrite the return value; the another function isoverride_function_with_return() which is to override the probedfunction returning and jump to its caller.Test log: cd /sys/kernel/debug/fail_function/ echo sys_clone > inject echo 100 > probability echo 1 > interval ls /[ 108.644163] FAULT_INJECTION: forcing a failure.[ 108.644163] name fail_function, interval 1, probability 100, space 0, times 1[ 108.647799] CPU: 0 PID: 104 Comm: sh Not tainted 5.8.0-rc5+ #46[ 108.648384] Call Trace:[ 108.649339] [<8005eed4>] walk_stackframe+0x0/0xf0[ 108.649679] [<8005f16a>] show_stack+0x32/0x5c[ 108.649927] [<8040f9d2>] dump_stack+0x6e/0x9c[ 108.650271] [<80406f7e>] should_fail+0x15e/0x1ac[ 108.650720] [<80118ba8>] fei_kprobe_handler+0x28/0x5c[ 108.651519] [<80754110>] kprobe_breakpoint_handler+0x144/0x1cc[ 108.652289] [<8005d6da>] trap_c+0x8e/0x110[ 108.652816] [<8005ce8c>] csky_trap+0x5c/0x70-sh: can't fork: Invalid argumentSigned-off-by: Guo Ren <guoren@linux.alibaba.com>Cc: Arnd Bergmann <arnd@arndb.de> List of files: /linux-6.15/arch/csky/lib/error-inject.c Tue, 28 Jul 2020 16:30:46 +0000 Guo Ren <guoren@linux.alibaba.com>